<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .page-header{
        height: 50px;
        background-color: rebeccapurple;
        width: 100%;
        }
        .page-body .menu{
         height: 800px;
         background-color: antiquewhite;
         float: left;
         width: 20%;
        }
        .page-body .content{
         height: 800px;
         background-color: cornflowerblue;
         float: left;
         width: 80%;
        }
        .page-footer{
         height: 50px;
         background-color: darkcyan;
         float: left;
         width: 100%;
        }
    </style>
</head>
<body>
<h1>商城</h1>
<div>
    <div class="page-header"></div>
    <div class="page-body">
        <div class="menu">
            <a href="/book/publisher/">出版社</a><br/>
            <a href="/book/author/">作者</a><br/>
            <a href="/book/book/">书籍</a><br/>
        </div>
            {% block content %}
            {% endblock %}
    </div>
    <div class="page-footer"></div>
</div>
</body>
</html>